Hybridoma proteins (HP) with binding characteristics of high specificity and affinity for oligosaccharides would be invaluable-reagents in the study of oligosaccharide localization, synthesis and excretion. Additionally, such antibodies might be used to purify or assess homogeneity of oligosaccharides from biological samples (of urine, plasma, tumors, etc.). High affinity characteristics of HP might be advantageously utilized for quantitative radioimmunoassays via isotope dilution techniques. Glycoconjugates of a urinary glucose-containing tetrasaccharide-Glc Alpha 1-6Glc Alpha 1-4Glc Alpha 1-4 Glc and, also, a milk oligosaccharide lacto-N-fucopentaose III (LNFIII) linked to keyhole-limpet hemocyanin (KLH) or edestin have been used to examine the feasibility of this hybridoma approach to carbohydrate-structural analysis.